1. Field of the Invention
This invention relates generally to interactive video games and, more specifically, to apparatus for utilizing sound location information in the video game program and adapting a video game system for utilizing that sound location information.
2. Description of the Background
Interactive video games are now so well-known and commonplace that practically everyone has either played one of these games or has watched such games being played by others. Video games are available for use at home utilizing the regular television receiver or television monitor that is present in the home, or video games can be played in an arcade-type situation, in which each game has its own video screen and sound playback equipment.
Generally, although the interactive video games have now become sophisticated in their video displays, the audio portion of the game has not been as well developed. For that reason, it has been proposed to employ a sound imaging system, such as described and disclosed in U.S. Pat. No. 5,046,097 issued Sep. 3, 1991 and assigned to the assignee hereof. The disclosure of this above-identified patent application is incorporated herein by reference. In that application, a system is disclosed whereby the apparent location of sounds produced by two, spaced-apart speakers can be controlled so that the location of the sound source appears to the listener to be at a point other than the actual location of the speakers. This is accomplished by using empirically derived transfer functions that operate on a plurality of monaural input signals. The two-channel output signals produced by each transfer function, each with a frequency dependent differential phase and amplitude relationship, are summed to provide a two-channel output. The phase and amplitude adjustments are made individually for successive frequency bands over the audio spectrum. The transfer function can be implemented by a digital filter and, generally, a separate transfer function is required for each discrete location from which the sound apparently emanates. Use of this sound location system will greatly enhance the audio program material that goes along with the interactive video game. Nevertheless, the interconnection of the video game subsystems and the replacement of some existing subsystems to provide a commercially viable system has become problematical.